The purpose of this study is to evaluate new techniques for measuring lung function during exercise in people with asthma. We have studied 32 subjects under specific aim 1, and we have submitted that work for publication. This study compared methods for assessing exericse induced asthma. We found that pulmonary resistance measurements and spirometry are roughly comparable, though there are minor effects of changing lung volumes during exercise and effects of increasing ventilatory flows that one must account for when using resistance measurements.